Brake-shoe.



UNITED STATES PATENT OFFICE.

JOSEPH ALEXANDER PANTON, 0F WATERLOO, NEAR LIVERPOOL, ENGLAND.

BRAKE-SHOE.

To all whom it may concern:

Be it known that I, JosErH ALEXANDER PAN'roN, a subject of the King of Great Britain, and resident of W'aterloo, near Liverpool, England, have invented certain new and useful Improvements in Brake- Shoes, of which the following is a specification.

This invention has reference to brake shoes of that type wherein the separable wearing sole or shoe proper is provided with a reinforcing strip or backing of wrought metal, said backing having a lug for securing the shoe in position on the brake head.

The particular objects ofthe present invention are to provide means for preventing the lug and the part of the backing in proximity to the lug from being burned during the operation of casting the shoe, and to produce a shoe the metal of which is double chilled, that is, from the back as well as the front or wearing face, all as hereinafter more particularly set forth.

The invention is illustrated. in the accompanying drawings, in which,

Figure l. is a view showing by way of eX- ample one kind of wrought sheet metal backing with attaching lug to be aiiiXedto the cast shoe. Fig. V2. is a longitudinal medial section showing the shoe cast on such a backing, the protecting and chill block for the lug being shown in position for casting. Fig. 8. is a corresponding section showing a finished brake shoe before wear. Fig. 4. is a longitudinal section showing such a brake shoe after wear has taken place.

Brake shoes have been previously proposed in which a rear attaching lug such as l has been constructed either integrally with or separate from a wrought metal backing such as 2, a cast metal shoe such as 3 being formed on the backing. But in such cases there has always been a liability of the lug being burned and weakened during the process of casting. Further, brake shoes have been made having alternate chilled and soft iron portions on their wearing surfaces, such alternate arrangement of the chilled and soft iron portions giving the most satisfactory results in practice, but such chilled portions when set up from the wearing face could not be allowed to penetrate very deeply into the metal of the shoe, as otherwise, the shoe would become too brittle at cross sections through the chills and liable to break Specification of Letters Patent.

Application filed March 1'?, 1910.

Patented July 5, 1910. Serial No. 549,995.

off. Consequently when the shoes had worn down to such an extent as to cause the chills to disappear, the whole wearing surface of the shoe was of soft iron and quickly wore down. To avoid this eventual elimination of the chills by wear it has been proposed to chill the ends of the shoe sompletely through from wearing surface to back. It is disadvantageous however to have chills on the eXtreme tips of the shoes, such hard tips acting to score and cut the tires of the wheels. This can only be prevented by forming the chill in a surrounding of soft metal.

According to this invention, when the shoe 3 is being cast on the backing 2, a protecting chill block 4; shaped to fit closely around the lug l and the local portions of the backing near the lug, is placed in the sand in a position corresponding to the rear or back of the shoe, the usual chill blocks 5 being disposed at the front of the shoe, a short distance in from the ends, so as to allow for soft metal being left at the extreme tips, but staggered with reference to the back chill bloc-k. With such an arrangement when the shoe is being cast the back chill 4 protects the lug l and the local portion of the backing 2 from being burned, thus maintaining tlie strength of the lug and the backing, and throws a chill G from the'back surface of the shoe. This rear chill 6 is made to penetrate only to approximately the medial line wat, or halfway into the shoe. The front chills 7 are similarly made to penetrate from the frontor wearing surface 8 to about the medial line aa, or half way into the shoe. By this means a shoe is produced chilled from the back and front as in Fig. 3, the chills being staggered on the `back and front alternately. Such a shoe fulfils the required conditions of having alternate soft and chilled iron sections on its wearing surface continuously throughout its life, that is, until worn down to the backing, since, when the face chills 7 have been completely worn away as in Fig. 4L. the rear chill 6 comes into wear, and when in wear both front and rear chills alternate at the wearing surface with soft metal, and are surrounded on the wearing surface with soft metal.

I claim:

l. A cast metal brake shoe provided with a reinforcing backing of wrought metal and having chills formed in the front or wearing surface and in the back thereof, said k1ro i chills penetrating` about into theV shoeend being staggered( on the front and back Surfaces -filternitelyi 2. A cast metal brake shoe provided with A L reinforcing backing of Wrought metal and having face chills disposed on the ivesiringV f surface ashort distance in from the endsV and VeV back chill Vdisposed centrally, said front and back chills penetrating about half- Way into-the nietel of the shoe.

"13. In a cast metal brake` shoe provided Y with a reinforcing backing and rear attaching lug of Wrought metal, an attaching lug of the slioeby said protecting chill block and face chills formed in the Wearing suraceof athe shoe.

In testimony whereof I affix iny signature in presence of two witnesses.

JOSEPH ALEXANDER IANTON.

`Wit1iesses:'

A. DAvIEs, FRED NAYLOR, 

